The clairvoyant said: "There seems to be one particular area that's giving people the creeps. People have seen and felt things."

Mr Wey said: "Michael instantly detected someone standing there and he was suspicious there was something quite unusual there.

"The conclusion is, we can't prove it is haunted because of strong electromagnetic fields, which can cause the illusion of being haunted, the feeling of being touched or watched, but there is definitely paranormal activity.

"People feel uneasy when they enter the building and the hairs on the back of your neck go up.

"A lot of people don't like going in there. You can hear voices in the tunnels."

Mr Wey said the figure, which followed workers about often laughed at them and staff could hear "muffled conversations" coming from behind the tunnel walls.

Another worker said: "I believe in ghosts and I'm sure there's something in there. I dread doing the night shift.

"It's not funny going to work and worrying that a zombie might be around the corner."

A Southern Water spokesman said: "Mr Wey has a personal interest in the afterlife and found our underground site at Eastbourne somewhat spooky.